The present invention relates to a new and improved construction of segment exchanger apparatus for a continuous casting installation which is of the type comprising an at least partially curved strand guide or roller apron subdivided into segments. The segments are mounted in stationary guides, and an inner track section, pivotable about an essentially horizontal axis or pivot shaft, can be selectively adjusted at any one of the stationary guides. The invention further relates to a novel method of operating such segment exchanger apparatus.
The parts of the strand guide or roller apron of a continuous casting installation which encompass at least one pair of rolls or other conventional guide means, in the case of a curved arrangement, are usually referred to as segments. In order to assemble and dismantle these segments there are known to the art the most different constructions of segment exchanger equipment.
With a state-of-the-art segment exchanger apparatus the curved, successively arranged strand guide segments are mounted in stationary guides. These stationary guides enable any selected segment which is to be dismantled to initially be guided in a direction perpendicular to the direction of strand travel in the direction of the center of curvature of the strand guide, and thereafter to be deflected into a vertical path of travel. The segment is moved by the crane located at the casting platform. Since there is required a separate guide for each segment, there are needed a multiplicity of such guides. This impairs the accessibility to the strand guide or roller apron. Furthermore, the casting platform must be maintained free at a large region near to the continous casting mold, because the guides operatively associated with each segment must be able to guide the segments, at different locations, through openings provided at the casting platform. Furthermore, the casting platform also must be unobstructed so that the ladle operator can travel with the ladle over the relevant region of the casting platform.
These drawbacks should be avoided according to a heretofore known further development of this structure. The curved, stationary guides which are operatively correlated with each segment, in this case coact with a track section which is pivotable about a horizontal axis or pivot shaft. The inner pivotable track section is arranged on a carriage which can travel upon the casting platform. Upon the carriage there is arranged a respective winch for pivoting the track section and for withdrawing the segments. During the segment exchange operation the segment is pulled from the stationary guide onto the pivotable inner guide track and, by pivoting the track section into a horizontal position, the segment is lifted onto the casting platform. Thereafter, the segment is raised by a crane from the pivotable track section. The assembly work is accomplished in the reverse sequence.
On the one hand, this solution is expensive owing to the travelling arrangement of the pivotable inner track section, and, on the other hand, the entire displacement path of the carriage at the casting platform must be maintained unobstructed, so that at any time when a disturbance arises, it is possible to exchange segments. The transfer of the segment from the winch to the crane and from the crane to the winch requires each time manual effort. Finally, the inner track section, during each segment exchange, must be pivoted throughout its entire length through an opening in the casting platform, so that, on the one hand, it is necessary to remove large cover elements at the casting platform, and, on the other hand, the pivotable track section must be alined twice at the stationary guides operatively associated with the segments to be exchanged. This results in a poor utilization of the surface of the casting platform, increases the danger of accidents by virtue of the large openings which are present in the casting platform, and furthermore, increases the time needed for the segment exchange operation.